Microsoft Macro Assembler 6.x

The Microsoft Macro Assembler (MASM) is an x86 assembler that uses the Intel syntax for MS-DOS and Microsoft Windows. For a time, it competed with Borland Turbo Assembler. IBM re-branded early versions under the name IBM Macro Assembler. Later versions were bundled with Microsoft Visual Studio.

Release notes

version 6.11 is the last version of MASM that will run under MS-DOS

Installation instructions

MASM 6.14 includes support for the Intel Pentium Pro processor, the Intel MMX architecture, AMD 3D Technology, and Intel Internet Streaming SIMD Extensions.

Due to changes in the MS-DOS extender used in earlier versions of MASM, MASM 6.14 does not run on Windows 3.1x or MS-DOS. Either Windows NT or Windows 95 is required to run MASM 6.14.

Product type
Release date
User interface
Download count
32 (22 for release)


Download name Version Language Architecture File size Downloads
Microsoft Macro Assembler 6.0 (3.5-720k) 6.0 English 3.96MB 2
Microsoft Macro Assembler 6.0 (5.25-1.2mb) 6.0 English 3.97MB 2
Microsoft Macro Assembler 6.0b (3.5-1.44m) 6.0b English 4.04MB 0
Microsoft Macro Assembler 6.1 Manuals 6.1 English 4.13MB 5
Microsoft Macro Assembler 6.11 (3.5) 6.11 English 4.86MB 10
Microsoft Macro Assembler 6.14 Update 6.14 Upgrade English 1.37MB 3


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